The invention is directed to a process for the separation and purification of platinum group metals from base metals and for separation of platinum group metals from each other from aqueous, acidic solutions by means of an organic extraction agent in a solvent that is non-miscible with water.
The process known at the present time for the separation and purification of the platinum group metals platinum, palladium, rhodium, ruthenium, iridium, and osmium from acidic, aqueous solutions which also contain base metals require a large number of individual process steps and are very time consuming. Besides the difficulties increase in the known process for separating platinum metals with the number of such metals and the base metals present such as copper, iron, nickel, cobalt, zinc, or manganese.
Known processes operate in part with organic precipitation and extraction agents, such as, e.g. mercaptopyridine-N-oxide (U.S. Pat. No. 4,368,073), but these reagents are frequently only slightly specific or not usable in general for all platinum group metals.
Therefore it was the problem of the present invention to provide a process for the separation and purification of platinum group metals from base metals and to separate the platinum group metals from each other from aqueous, acidic solutions by means of an organic extraction agent in a solvent which is not miscible with water, with which in a simple manner there are separated and purified as quantitatively as possible all platinum group metals.